Deprived of courage, spirit, or confidence; disheartened or discouraged.
From dis- (prefix negating action) plus mettle (courage or fortitude), with the past tense -ed suffix; 'mettle' comes from a variant of 'metal' metaphorically referring to a person's inner strength and quality.
'Dismettled' and 'mettle' share a weird origin—they come from the same root as 'metal,' because medieval English speakers thought of courage as a quality like the strength of steel, giving us a weird metaphor where courage is literally a metal in your spirit.
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